Refine domain nullable rules for PostgreSQL reflection

Fixed issue in PostgreSQL reflection where a column expressing "NOT NULL"
will supersede the nullability of a corresponding domain.

Fixes #6161

Change-Id: I1a3de49afcdb952f71bd7a7cc7b264513c93eff5
(cherry picked from commit ab61d66dee9b3c3639907557852908858daacb6f)

diff --git a/doc/build/changelog/unreleased_13/6161.rst b/doc/build/changelog/unreleased_13/6161.rst
new file mode 100644 (file)
index 0000000..df41b85
--- /dev/null
+++ b/doc/build/changelog/unreleased_13/6161.rst
@@ -0,0 +1,7 @@
+.. change::
+    :tags: bug, postgresql, reflection
+    :tickets: 6161
+    :versions: 1.4.4
+
+    Fixed issue in PostgreSQL reflection where a column expressing "NOT NULL"
+    will supersede the nullability of a corresponding domain.

diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index a33435216e1f78cbaa45e25e0ceff4a35d732ebb..93ee1fa1ab089402dfebd4fc546dc2979fe1ee5c 100644 (file)
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -3213,8 +3213,9 @@ class PGDialect(default.DefaultDialect):
                 attype, is_array = _handle_array_type(attype)
                 # strip quotes from case sensitive enum or domain names
                 enum_or_domain_key = tuple(util.quoted_token_parser(attype))
-                # A table can't override whether the domain is nullable.
-                nullable = domain["nullable"]
+                # A table can't override a not null on the domain,
+                # but can override nullable
+                nullable = nullable and domain["nullable"]
                 if domain["default"] and not default:
                     # It can, however, override the default
                     # value, but can't set it to null.

diff --git a/test/dialect/postgresql/test_reflection.py b/test/dialect/postgresql/test_reflection.py
index b92d46c7bea7f284614e861f95ba4b0bc317f188..dc1d517905091f1d417d74d04ef755dad6dfc1da 100644 (file)
--- a/test/dialect/postgresql/test_reflection.py
+++ b/test/dialect/postgresql/test_reflection.py
@@ -32,6 +32,7 @@ from sqlalchemy.testing import mock
 from sqlalchemy.testing.assertions import assert_raises
 from sqlalchemy.testing.assertions import AssertsExecutionResults
 from sqlalchemy.testing.assertions import eq_
+from sqlalchemy.testing.assertions import is_
 
 
 class ForeignTableReflectionTest(fixtures.TablesTest, AssertsExecutionResults):
@@ -276,6 +277,9 @@ class DomainReflectionTest(fixtures.TestBase, AssertsExecutionResults):
             "CREATE DOMAIN enumdomain AS testtype",
             "CREATE DOMAIN arraydomain AS INTEGER[]",
             'CREATE DOMAIN "SomeSchema"."Quoted.Domain" INTEGER DEFAULT 0',
+            "CREATE DOMAIN nullable_domain AS TEXT CHECK "
+            "(VALUE IN('FOO', 'BAR'))",
+            "CREATE DOMAIN not_nullable_domain AS TEXT NOT NULL",
         ]:
             try:
                 con.execute(ddl)
@@ -303,6 +307,11 @@ class DomainReflectionTest(fixtures.TestBase, AssertsExecutionResults):
             "CREATE TABLE quote_test "
             '(id integer, data "SomeSchema"."Quoted.Domain")'
         )
+        con.execute(
+            "CREATE TABLE nullable_domain_test "
+            "(not_nullable_domain_col nullable_domain not null,"
+            "nullable_local not_nullable_domain)"
+        )
 
     @classmethod
     def teardown_class(cls):
@@ -321,6 +330,10 @@ class DomainReflectionTest(fixtures.TestBase, AssertsExecutionResults):
         con.execute('DROP DOMAIN "SomeSchema"."Quoted.Domain"')
         con.execute('DROP SCHEMA "SomeSchema"')
 
+        con.execute("DROP TABLE nullable_domain_test")
+        con.execute("DROP DOMAIN nullable_domain")
+        con.execute("DROP DOMAIN not_nullable_domain")
+
     def test_table_is_reflected(self):
         metadata = MetaData(testing.db)
         table = Table("testtable", metadata, autoload=True)
@@ -343,6 +356,12 @@ class DomainReflectionTest(fixtures.TestBase, AssertsExecutionResults):
             not table.columns.answer.nullable
         ), "Expected reflected column to not be nullable."
 
+    def test_nullable_from_domain(self):
+        metadata = MetaData(testing.db)
+        table = Table("nullable_domain_test", metadata, autoload=True)
+        is_(table.c.not_nullable_domain_col.nullable, False)
+        is_(table.c.nullable_local.nullable, False)
+
     def test_enum_domain_is_reflected(self):
         metadata = MetaData(testing.db)
         table = Table("enum_test", metadata, autoload=True)